I am new and so is my status in owning a Mercedes. I have fallen for this car a 2005 C230K. I cant stop seeing the potential and find myself saying, "she already has everything". My main goal for mods is to achieve 40mpg, I have consistanly monitored the mpg and over the last month I have achieved 36mpg consistantly. I have averaged 34+mpg over 530 miles traveled. The only mod I have incorporated is a K&N air filter swap. Before this the max mpg was 34mpg which was the first week I drove the vehicle. I plan to put in a new spark plugs soon. Anyone have any other possibilities for me to reach my goal of 40mpg? Another thing is I watch how I drive, careful acceleration and I never go ever the posted speed limit, which is very difficult. I have new radials also.